I think there is a DIY for the poorman's throttle body in the FAQ section.

TB spacers won't do squat on our trucks, aside from lighten your wallet.

 

for what it's worth and it doesn't mean anything-

Dan Arcand still makes TB's.. I just sent him my core today.. I put a 52mm on last week..

the only gain there can possibly be is on the extreme top end- there is zero gain down low.. You don't have to push your foot so far as to let the air in is the only advantage.. I have plans in the near future if you're wondering why I even got it...

I did the keg mod as well... I don't know that it did anything and I don't know anyone who really does with any certainty, and the biggest reason why is because when most people are 'in there', it's due to a leaky plenum- so the gains experienced are most likely because of the plenum gasket repair..

I've recently done a TON of research on this subject.. This is ALL theory (and me repeating that theory, as I have NO experience)- and based on the opinions of the 'experts' I asked... (in this case I truly do believe them experts fwiw).. If you truly want to squeeze more performance out of a kegger (or ANY manifold).. and we're talking upwards of 10 horses on these engines- port match the gasket to the runner opening.. I'm guessing it will take about as long as cutting the runners (it took me about 2~3 hours to keg-mod, but I DID NOT port match).. The guys with the know how and the patience to do the math estimate that 1 cfm extra of flow is equal to 1-2 HP..

All of this said- and another fwiw- I've located an F1 air-gap for $300- and I'm nailing it (and yes it's for MPFI).. I plan on port matching it and seeing what it offers.. THE ONLY reason I'm doing this is because I found it so cheap, and because I'm bored- and the 4.56's should play into it as well as I spend more time in the 2.2k~2,8k RPM range with those R&P's- where the air gap is comfortable...

It's also been bounced around and presented to me- though these guys are pretty much split on the subject- that a plenum turtle is beneficial.. The split amongst the fellas, curiously, is the same split that separates the 'top end strip' guys from the 'towing and trail' guys.. The top end guys abhor it while the towers/trailers love it.. The notion is creating a better and more defined 'column' of air in any RPM range which means more efficiency.. The top end guys say it 'removes air reserve', which is also true as that is basically what a plenum is all about anyway..

It's always a floggin' balance huh? Why can't I have 400HP/600TQ under my foot that runs on pump 87 and gets 24MPG??? Dang it..

 

For port matching to be truly effective, (or, more accurately.... gasket matching I suppose....) you need to do BOTH sides. Manifold, AND Head. If you only do one side, you may actually end up with WORSE airflow, as the large port merges to the smaller one, you get a boatload of turbulence.

 

yup - and that is coming too.. I'm looking at heads right now.. One train of thought is pulling to to stay with 1.92 intake valves, while another is pushing me to 2.02.. but this topic deserves it's own thread.. either way though, they will also be matched..